1. Field of the Invention:
This invention relates to a stable suppository containing 3-formylamino-4-hydroxy-.alpha.-[N-(1-methyl-2-p-methoxyphenylethyl)aminom ethyl]benzyl alcohol.1/2fumarate mono-hydrate (hereinafter, referred to as BD-40A).
2. Description of the Prior Art:
BD-40A possesses a strong and prolonged bronchodilator activity and is very useful as an antiasthmatic agent (see, U.S. Pat. No. 3,994,974). In general, when a patient has an asthmatic spasm, it is sometimes very difficult to orally administer medicaments and even if the patient can take a medicament, it sometimes happens that the patient disgorges the medicament by coughing and hence the desired purpose cannot be attained. Also, an asthmatic patient has a tendency of being afflicted with a spasm at night and for prophylaxis, a medicament is sometimes administered before sleeping or, in case of infants, etc., after sleeping. Therefore, the development of suppositories containing BD-40A which can be parenterally administered had been desired.
However, BD-40A is unexpectedly unstable in the form of a suppository although BD-40A itself is chemically stable. Decomposition of BD-40A occurs when the compound is incorporated into an ordinary suppository base such as polyethylene glycol, glycerogelatin, a glycerol triester of a higher fatty acid [This triester usually includes a small quantity of mono- and di-ester. As such substance, for example, "semi-synthetic glycerides" (Frech pharmacopoeia), "Witepsol" (registered trademark, made by Dynamit Nobel A.G.) are illustrated, and these include a small quantity of mono- and di-ester; hereinafter, the term "a glycerol triester of a higher fatty acid" is used in this meaning] as well as when it is formulated with additives such as a surface active agent, a higher fatty alcohol, etc., and hence it was generally very difficult to use BD-40A for practical purposes in the form of a suppository.